Light emitting device and light emitting device package having the same

ABSTRACT

Disclosed are a light emitting device. The light emitting device includes first and second light emitting cells on a conductive support member and having a hole. The first and second light emitting cells includes first and second semiconductor layers, and an active layer. First and second conducive layers are between the first light emitting cell and the conductive support member, and a third and fourth conductive layers are between the second light emitting cell and the conductive support member. First insulating layer is between the second and fourth conductive layers and the conductive support member. Second insulating layer is disposed in the hole. The second conductive layer is electrically connected to the first light emitting cells through the hole and the third conductive layer.

This application is a Continuation of co-pending U.S. patent applicationSer. No. 12/870,911 filed on Aug. 30, 2010, which claims priority under35 U.S.C. 119 to Korean Patent Application No. 10-2009-081112 filed onAug. 31, 2009, which is hereby incorporated by reference in itsentirety.

BACKGROUND

The embodiment relates to a light emitting device and a light emittingdevice package having the same.

Groups III-V nitride semiconductors have been extensively used as mainmaterials for light emitting devices, such as a light emitting diode(LED) or a laser diode (LD), due to the physical and chemicalcharacteristics thereof. In general, the groups III-V nitridesemiconductors include a semiconductor material having a compositionalformula of In_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, and 0≦x+y≦1).

The LED is a semiconductor device, which transmits/receives signals byconverting an electric signal into infrared ray or light using thecharacteristics of compound semiconductors. The LED is also used as alight source.

The LED or the LD using the nitride semiconductor material is mainlyused for the light emitting device to provide the light. For instance,the LED or the LD is used as a light source for various products, suchas a keypad light emitting part of a cellular phone, an electricsignboard, and an illumination device.

SUMMARY

The embodiment provides a light emitting device for AC voltage and alight emitting device package having the same.

The embodiment provides a light emitting device having m light emittingcells (4≧m) driven with AC voltage and a light emitting device packagehaving the same.

The embodiment provides a light emitting device having m light emittingcells (4≧m) connected to each other in series and a light emittingdevice package having the same.

The embodiment provides a light emitting device including a first grouphaving a plurality of light emitting cells connected to each other inseries and a second group having a plurality of light emitting cellsconnected to each other in series, in which the first group is connectedparallel to the second group, and a light emitting device package havingthe same.

A light emitting device according to the embodiment includes a pluralityof light emitting cells including a first and second light emittingcells spaced apart from each other, each of the first and second lightemitting cells including a first semiconductor layer, a secondsemiconductor layer under the first semiconductor layer, and an activelayer between the first semiconductor layer and the second semiconductorlayer; a conductive support member under the first and second lightemitting cells; a first conducive layer between the first light emittingcell and the conductive support member; a second conductive layerbetween the first conductive layer and the conductive support member; athird conductive layer between the second light emitting cell and theconductive support member; a fourth conductive layer between the thirdconductive layer and the conductive support member; a first insulatinglayer between the second and fourth conductive layers and the conductivesupport member; a first hole disposed in the active layer and the secondsemiconductor layer of the first light emitting cell; a second holedisposed in the active layer and the second semiconductor layer of thesecond light emitting cells; and a second insulating layer disposed inthe first hole and the second hole, wherein the second conductive layerincludes a first portion disposed in the first hole and is electricallyconnected to the first semiconductor layer of the first light emittingcells by the first portion and the third conductive layer.

A light emitting device according to the embodiment includes a pluralityof light emitting cells including a first conductive semiconductorlayer, an active layer under the first conductive semiconductor layer,and a second conductive semiconductor layer under the active layer; aplurality of conductive contact layers under the light emitting cells; afirst electrode layer connected to the first conductive semiconductorlayer of a first light emitting cell of the plural light emitting cells;a plurality of second electrode layers under the conductive contactlayers, a portion of the second electrode layers being connected to thefirst conductive semiconductor layer of a next light emitting cell ofthe plural light emitting cells; a third electrode layer under theconductive contact layer disposed under a last light emitting cell ofthe plural light emitting cells; an electrode connected to a centralsecond electrode layer of the plural second electrode layers; aninsulating layer around the first to third electrode layers; and aconductive support member under the insulating layer, the conductivesupport member being connected to the first and last light emittingcells of the plural light emitting cells.

A light emitting device package according to the embodiment includes abody; a plurality of lead electrodes on the body; a light emittingdevice connected to the lead electrodes; and a molding member formolding the light emitting device, wherein the light emitting deviceincludes a plurality of light emitting cells including a firstconductive semiconductor layer, an active layer under the firstconductive semiconductor layer, and a second conductive semiconductorlayer under the active layer; a first electrode layer connected to thefirst conductive semiconductor layer of a first light emitting cell ofthe plural light emitting cells; a plurality of second electrode layersunder the light emitting cells, a portion of the second electrode layersbeing connected to the first conductive semiconductor layer of anadjacent light emitting cells; a third electrode layer under a lastlight emitting cell of the plural light emitting cells; a firstelectrode connected to the first electrode layer; a second electrodeconnected to the third electrode layer; an insulating layer around thefirst to third electrode layers; and a support member under theinsulating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a light emitting device according tothe first embodiment;

FIG. 1A is a sectional view showing a light emitting device according toan another example of the first embodiment;

FIG. 2 is a circuit view showing an AC driving circuit of a lightemitting device shown in FIG. 1;

FIGS. 3 to 12 are sectional views showing the procedure formanufacturing a light emitting device shown in FIG. 1;

FIG. 13 is a sectional view showing a light emitting device according tothe second embodiment;

FIG. 14 is a sectional view showing a light emitting device according tothe third embodiment; and

FIG. 15 is a sectional view showing a light emitting device packageincluding a light emitting device shown in FIG. 1.

FIG. 16 is a perspective view illustrating an example of a displayapparatus provided with the light emitting device package of FIG. 15.

FIG. 17 is a perspective view illustrating another example of a displayapparatus provided with the light emitting device package of FIG. 15.

FIG. 18 is a perspective view of a lighting apparatus provided with thelight emitting device package of FIG. 15.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of the embodiments, it will be understood that, whena layer (or film), a region, a pattern, or a structure is referred to asbeing “on” or “under” another substrate, another layer (or film),another region, another pad, or another pattern, it can be “directly” or“indirectly” on the other substrate, layer (or film), region, pad, orpattern, or one or more intervening layers may also be present. Such aposition of the layer has been described with reference to the drawings.

Hereinafter, the embodiments will be described with reference to theaccompanying drawings. The thickness and size of each layer shown in thedrawings may be exaggerated, omitted or schematically drawn for thepurpose of convenience or clarity. In addition, the size of elementsdoes not utterly reflect an actual size.

FIG. 1 is a side sectional view showing a light emitting deviceaccording to the first embodiment.

Referring to FIG. 1, the light emitting device 100 includes a pluralityof light emitting cells A1 to An and B1 to Bn, a conductive contactlayer 118, electrode layers 121 to 125, insulating layers 151, 155 and156, a first electrode 171, a second electrode 173 and a conductivesupport member 170.

The light emitting device 100 includes a first group 101 having at leastn light emitting cells A1 to An (n≧2) connected to each other in seriesand a second group 103 having at least n light emitting cells B1 to Bn(n≧2) connected to each other in series.

The light emitting cells A1 to An of the first group 101 and the lightemitting cells B1 to Bn of the second group 103 are formed on theconductive support member 170. The light emitting cells A1 to An and B1to Bn may have the same size or some light emitting cells have differentsizes. In addition, the light emitting cells A1 to An and B1 to Bn mayhave the same upper and lower widths or the upper widths are narrowerthan the lower widths of the light emitting cells A1 to An and B1 to Bn.

The light emitting cells A1 to An of the first group 101 are connectedto the light emitting cells B1 to Bn of the second group 103 in series.The light emitting cells A1 to An and B1 to Bn may have the same size ordifferent sizes, and the embodiment is not limited thereto.

The light emitting cells A1 to An and B1 to Bn can be arrayed in atleast one row or in the form of a matrix. In addition, the lightemitting cells A1 to An and B1 to Bn of the first and second groups 101and 103 may be driven under one driving mode or one operational periodof AC power.

The light emitting cells A1 to An and B1 to Bn of the first and secondgroups 101 and 103 may include a plurality of semiconductor layersincluding the group III-V compound semiconductors. For instance, thelight emitting cells A1 to An and B1 to Bn may include a firstconductive semiconductor layer 112, an active layer 114 under the firstconductive semiconductor layer 112, and a second conductivesemiconductor layer 116 under the active layer 114.

For instance, the light emitting cells A1 to An and B1 to Bn may includeGaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP,or AlGaInP. If the first conductive semiconductor layer is an N typesemiconductor layer, the second conductive semiconductor layer is a Ptype semiconductor layer.

The first conductive semiconductor layer 112 is formed on the activelayer 114. The first conductive semiconductor layer 112 may havethickness larger than that of the second conductive semiconductor layer116. If the first conductive semiconductor layer 112 is the N typesemiconductor layer, the first conductive semiconductor layer 112 isdoped with N type dopant, such as Si, Ge, Sn, Se, or Te. A roughness 113can be formed on the top surface of the first conductive semiconductorlayer 112. The roughness 113 may include a concave-convex pattern. Theroughness 113 can improve the external quantum efficiency. In addition,since the electrode is not formed on the top surfaces of the lightemitting cells A1 to An and B1 to Bn, reduction of the external quantumefficiency caused by the electrode can be prevented.

A transmissive layer can be formed on the top surface of the firstconductive semiconductor layer 112. The transmissive layer includesmaterial having a refractive index lower than that of the firstconductive semiconductor layer 112. For instance, the transmissive layermay include insulating material and/or a transparent electrode layer,such as TCO (Transparent conductive oxide).

The active layer 114 is interposed between the first and secondconductive semiconductor layers 112 and 117 to emit the light having apredetermined wavelength band. The active layer 114 may have a singlequantum well structure, a multiple quantum well structure, a quantumwire structure, or a quantum dot structure. The active layer 114 mayhave a stack structure of a well layer/a barrier layer, such asInGaN/GaN, GaN/AlGaN, InGaN/InGaN, but the embodiment is not limitedthereto. The well layer may have a band gap lower than that of thebarrier layer.

A first conductive clad layer (not shown) may be formed between theactive layer 114 and the first conductive semiconductor layer 112. Thefirst conductive clad layer may include a GaN-based semiconductor andhave a band gap higher than that of the active layer 114.

A second conductive clad layer (not shown) may be formed between theactive layer 114 and the second conductive semiconductor layer 116. Thesecond conductive clad layer may include a GaN-based semiconductor andhave a band gap higher than that of the active layer 114.

The second conductive semiconductor layer 116 is disposed under theactive layer 114. The second conductive semiconductor layer 116 includesthe compound semiconductor doped with the second conductive dopant. Forinstance, the second conductive semiconductor layer 116 may include atleast one selected from the group consisting of GaN, InN, AlN, InGaN,AlGaN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. If thesecond conductive semiconductor layer 116 is a P type semiconductorlayer, the second conductive dopant includes the P type dopant such asMg, Zn, Ca, Sr or Ba.

A third conductive semiconductor layer (not shown) can be formed underthe second conductive semiconductor layer 116. The third conductivesemiconductor layer may include a semiconductor layer, which haspolarity opposite to that of the second conductive semiconductor layer.The third conductive semiconductor layer may include the semiconductorhaving polarity identical to that of the first conductive semiconductorlayer. Thus, the light emitting cells A1 to An and B1 to Bn may have oneof an N—P junction structure, a P—N junction structure, an N—P—Njunction structure, and a P—N—P junction structure. For the purpose ofconvenience, the lowest layer of the light emitting cells will bereferred to as the second conductive semiconductor layer 116.

In addition, a stepped portion, which exposes the first conductivesemiconductor layer 112 and a part of the top surface of the secondconductive semiconductor layer 116, is not formed in the light emittingcells A1 to An and B1 to Bn.

The second conductive semiconductor layer 116 is formed under the activelayer 114 and can be doped with the P type dopant, such as Mg, Be or Zn.The second conductive semiconductor layer 116 or the third conductivesemiconductor layer can be disposed at the lowest layer of the lightemitting cells A1 to An and B1 to Bn. For the purpose of convenience,the lowest layer of the light emitting cells will be referred to as thesecond conductive semiconductor layer 116.

The light emitting cells A1 to An and B1 to Bn can be spaced apart fromeach other by spacers 161. The spacer 161 interposed between the firstand second groups 101 and 103 may have a width equal to or differentfrom a width between light emitting cells.

The conductive contact layer 118 is formed under the second conductivesemiconductor layer 116 of the light emitting cells A1 to An and B1 toBn and the electrode layers 121 to 125 are formed under the conductivecontact layer 118. The conductive contact layer 118 includes an ohmiccontact layer. The conductive contact layer 118 may come into ohmiccontact with a lower surface of the second conductive semiconductorlayer 116. The conductive contact layer 118 may include one selectedfrom the group consisting of ITO (indium tin oxide), IZO (indium zincoxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide),IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO(aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zincoxide), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au, Ni/IrOx/Au/ITO, TCO(Transparent conductive oxide) and TCN (transparent conductive nitride).

The conductive contact layer 118 may include a plurality of patterns inwhich a low conductive layer (not shown) can be formed between patterns.The low conductive layer can be interposed between the patterns of theconductive contact layer 118 by using material, such as insulatingmaterial having conductivity lower than that of the conductive contactlayer 118. A number of the conductive contact layer 118 is identical toa number of the light emitting cells A1 to An and B1 to Bn.

The electrode layers 121 to 125 include one selected from the groupconsisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, W, Ti andcombination thereof. The electrode layers 121 to 125 can be prepared asa single layer or a multiple layer. The electrode layers 121 to 125 mayserve as reflective electrode layers having electric ohmic contactfunctions with high reflectivity (50% or above).

At least one of the electrode layers 121 to 125 is partially or fullydisposed under the light emitting cells A1 to An and B1 to Bn.

The first electrode layer 121 is disposed under the first light emittingcell A1 aligned at one side of the first group 101. Part 126 of thefirst electrode layer 121 makes contact with the first conductivesemiconductor layer 112 through the conductive contact layer 118, thesecond conductive semiconductor layer 116 and the active layer 114. Thefirst electrode layer 121 may include ohmic contact material at thecontact part between the first electrode layer 121 and the firstconductive semiconductor layer 112, but the embodiment is not limitedthereto.

One side of the first electrode layer 121 extends outward beyond thefirst light emitting cell A1 of the first group 101 and the firstelectrode 171 is electrically connected onto one side of the firstelectrode layer 121. The first electrode layer 121 may serve as a firstpad, and can be formed on one side of the first electrode layer 121. Inaddition, the first electrode 171 is formed on the first conductivesemiconductor layer 112 of the first light emitting cell A1, as depictedin FIG. 1A.

The second to fifth electrode layers 122 to 125 are disposed under thelight emitting cells A1 to An and B1 to Bn to serve as reflectivelayers. The second to fifth electrode layers 122 to 125 make contactwith the conductive contact layer 118 disposed under the light emittingcells A1 to An and B1 to Bn.

Parts 126 of the second to fourth electrode layers 122 to 124 makecontact with the first conductive semiconductor layer 112 of the nextlight emitting cell. The second to fourth electrode layers 122 to 124connect two adjacent light emitting cells in series.

The third electrode layer 123 electrically connects the first and secondgroups 101 and 103 with each other. In detail, the third electrode layer123 electrically connects the light emitting cell An of the first group101 with the light emitting cell Bn of the second group 103 in series.

The fifth electrode layer 125 makes contact with the conductive contactlayer 118 disposed under the first light emitting cell B1 of the secondgroup 103 and the other end of the fifth electrode layer 125 extends tothe other end of the first light emitting cell B1. The second electrode173 is electrically connected to the other side of the fifth electrodelayer 125. The second electrode 173 is electrically connected to theother end of the fifth electrode layer 125. The second electrode 173serves as a pad and is disposed on the other side of the fifth electrodelayer 125.

The first electrode 171 is opposite to or parallel to the secondelectrode 173 about the center of the light emitting device 100, but theembodiment is not limited thereto. The power applied to the firstelectrode 171 may have polarity opposite to that of the power applied tothe second electrode 173.

The first insulating layer 151 is formed on the first to fifth electrodelayers 121 to 125 to block the undesired contact among the first tofifth electrode layers 121 to 125, the light emitting cells A1 to An andB1 to Bn and the conductive contact layer 118.

The second insulating layer 155 is interposed between the first to fifthelectrode layers 121 to 125 and the conductive support member 170 toblock the undesired contact between the conductive support member 170and the first to fifth electrode layers 121 to 125. In addition, a partof the second insulating layer 155 prevents the ohmic contact layer 118of one light emitting cell from making contact with the electrode layerof another light emitting cell.

The third electrode layer 123 makes contact with an nth light emittingcell An of the first group 101, an nth light emitting cell Bn of thesecond group 103, and the conductive support member 170.

AC power can be supplied to the third electrode layer 123 and the secondelectrode 173, respectively, at the interval of half operational periodsuch that the first and second groups 101 and 103 can be alternatelyoperated at the interval of half operational period.

The light emitting cells A1 to An of the first group 101 are connectedto the light emitting cells B1 to Bn of the second group 103 in series.The first electrode 171 is connected to the first light emitting cell A1of the first group 101, the conductive support member 170 is connectedto the nth light emitting cell An, the second electrode 173 is connectedto the first light emitting cell B1 of the second group 103, and theconductive support member 170 is connected to the nth light emittingcell Bn.

The conductive support member 170 supports the light emitting device andincludes at least one selected from the group consisting of Cu, Au, Ni,Mo, Cu—W, Pd, In, W, Si, Ta, Nb, and carrier wafer such as Si, Ge, GaAs,ZnO, GaN, Ge₂O₃, or SiC.

The conductive support member 170 may have heat sink and conductivecharacteristics.

The conductive support member 170 can be coated or attached in the formof a sheet, but the embodiment is not limited thereto. The conductivesupport member 170 may have a thickness of about 30-500μm, but theembodiment is not limited thereto.

A bonding layer can be interposed between the conductive support member170 and the third electrode layer 123. The bonding layer may include atleast one of Ti, Cr, Ta, and an alloy thereof.

The third insulating layer 156 is formed around the light emitting cellsA1 to An and B1 to Bn to prevent the short between layers and cells. Inaddition, the third insulating layer 156 may cover the upper portion ofthe light emitting cells A1 to An and B1 to Bn.

The first to third insulating layers 151, 155 and 156 include insulatingmaterial, such as SiO₂, Si₃N₄, Al₂O₃, or TiO₂.

During the half operational period of the AC power, positive power isapplied to the conductive support member 170 so that the current flowsto the first electrode 171 through the nth to first light emitting cellsAn to A1 of the first group 101. Thus, the light emitting cells A1 to Anof the first group 101 may emit the light.

During the next half operational period of the AC power, negative poweris applied to the second electrode 173 so that the current flows to theconductive support member 170 through the nth to first light emittingcells Bn to B1 of the second group 103. Thus, the light emitting cellsB1 to Bn of the second group 103 may emit the light.

The level of the AC power applied to the light emitting device 100 maycorrespond to the sum of the driving voltage of the light emitting cellsAn to A1 and Bn to B1. For instance, about 60 light emitting cellshaving the driving voltage of about 3.5V can be connected to each otherin series under the AC voltage of 220V. That is, under the AC voltage of220V is applied, 30 light emitting cells A1 to An of the first group 101are connected to each other in series and 30 light emitting cells B1 toBn of the second group 103 are connected to each other in series. Thus,60 light emitting cells are connected to each other in series. Inaddition, under the AC voltage of 110V, 30 light emitting cells havingthe driving voltage of about 3.5V can be connected to each other inseries.

The driving voltage of the light emitting cells A1 to An and B1 to Bn ischangeable so that the number of light emitting cells is alsochangeable. In addition, the light emitting device 100 can be operatedwithout an additional rectifier. The number of light emitting cells ofthe first group 101 may be identical to or different from the number oflight emitting cells of the second group 103 according to the level ofthe positive voltage and the negative voltage under the AC powercondition.

According to the embodiment, the light emitting cells A1 to An and B1 toBn of at least two groups 101 and 103 having operational periodsdifferent from each other are formed on one conductive support member,so that the size of the light emitting device can be minimized and thecircuit of the light emitting device for the AC power can be simplified.In addition, the first group 101 can be connected to the second group103 of the light emitting device without using an additional wire.

Further, since the light emitting cells A1 to An and B1 to Bn can beconnected to each other through the electrode layers 121 to 125 disposedunder the light emitting cells A1 to An and B1 to Bn, it is notnecessary to provide metal on the light emitting cells A1 to An and B1to Bn.

The first and second groups 101 and 103 of the light emitting device 100can be prepared in the form of bars. In addition, the first and secondgroups 101 and 103 can be parallel to each other or can be bent by atleast one time. If the first and second groups 101 and 103 are parallelto each other, the first electrode layer 121 can be electricallyconnected to the fifth electrode layer 125. In this case, one of thefirst and second electrodes 171 and 173 can be omitted.

FIG. 2 is a circuit view showing a driving circuit of the light emittingdevice shown in FIG. 1.

Referring to FIG. 2, positive current I1 of AC power is applied to thefirst group 101 for the half operational period to sequentially drivethe light emitting cells of the first group 101 from the nth lightemitting cell An to the first light emitting cell A1. In addition,negative current I2 of AC power is applied to the second group 103 forthe remaining half operational period to sequentially drive the lightemitting cells of the second group 103 from the nth light emitting cellBn to the first light emitting cell B1. In this manner, the lightemitting cells A1 to An and B1 to Bn of the first and second groups 101and 103 can be alternately turned on/off during one operational periodof the AC power.

A resistor and a rectifier circuit can be provided between the AC powerterminal and the light emitting device, and the embodiment is notlimited thereto. In addition, the light emitting device 100 can drivethe first group 101 separately from the second group 103.

FIGS. 3 to 12 are sectional views showing the method for manufacturingthe light emitting device shown in FIG. 1. In the following description,the manufacturing process for the first group of the light emittingdevice will be explained with reference to a plurality of light emittingcells and the method for manufacturing the second group will be omittedin order to avoid redundancy.

Referring to FIG. 3, the substrate 110 is loaded into growth equipmentand a group II to VI compound semiconductor is formed on the substrate110 in the form of a layer or a pattern.

The growth equipment may be selected from the group consisting of E-beamevaporator, PVD (physical vapor deposition), CVD (chemical vapordeposition), PLD (plasma laser deposition), dual-type thermalevaporator, sputtering, and MOCVD (metal organic chemical vapordeposition). However, the embodiment is not limited to the growthequipment.

The substrate 110 may include an insulating substrate or a conductivesubstrate. For instance, the substrate 110 may include one selected fromthe group consisting of Al₂O₃, GaN, SiC, ZnO, Si, GaP, InP, Ga₂O₃, andGaAs. A concave-convex pattern can be formed on the top surface of thesubstrate 110.

In addition, a layer or a pattern including a group II to VI compoundsemiconductor can be formed on the substrate 110. For instance, at leastone of a ZnO layer (not shown), a buffer layer (not shown) and anundoped semiconductor layer (not shown) can be formed on the substrate110. The buffer layer or the undoped semiconductor layer can be formedby using the group III-V compound semiconductor. The buffer layer mayreduce the lattice constant difference relative to the substrate, andthe undoped semiconductor layer may include an undoped GaN-basedsemiconductor. For the purpose of convenience, the following descriptionwill be made on the assumption that the first conductive semiconductorlayer 112 is formed on the substrate 110.

A plurality of compound semiconductors are formed on the substrate 110for the light emitting cells. The first conductive semiconductor layer112 is formed on the substrate 110, the active layer 114 is formed onthe first conductive semiconductor layer 112, and the second conductivesemiconductor layer 116 is formed on the active layer 1140.

The first conductive semiconductor layer 112 may include a group III-Vcompound semiconductor doped with a first conductive dopant. Forinstance, the first conductive semiconductor layer 112 may include oneselected from the group consisting of GaN, AlN, AlGaN, InGaN, InN,InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. If the firstconductive semiconductor layer 112 is an N type semiconductor layer, thefirst conductive dopant is an N type dopant, such as Si, Ge, Sn, Se, orTe. The first conductive semiconductor layer 112 may have a single layerstructure or a multi-layer structure, but the embodiment is not limitedthereto.

The active layer 114 is disposed on the first conductive semiconductorlayer 112. The active layer 114 may have a single quantum wellstructure, a multiple quantum well structure, a quantum dot structure ora quantum wire structure. The active layer 114 may have a stackstructure including a well layer and a barrier layer, such as an InGaNwell layer/GaN barrier layer, a GaN well layer/AlGaN barrier layer, oran InGaN well layer/InGaN barrier layer. This stack structure mayinclude 2-30 pairs of the well/barrier layers, but the embodiment is notlimited thereto. The well layer may include material having band gaplower than that of the barrier layer.

A first conductive clad layer (not shown) may be formed between theactive layer 114 and the first conductive semiconductor layer 112. Thefirst conductive clad layer may include a GaN-based semiconductor andhave a band gap higher than that of the active layer 114.

A second conductive clad layer (not shown) may be formed between theactive layer 114 and the second conductive semiconductor layer 116. Thesecond conductive clad layer may include a GaN-based semiconductor andhave a band gap higher than that of the active layer 114.

The second conductive semiconductor layer 116 is formed on the activelayer 114. The second conductive semiconductor layer 116 includes thegroup III-V compound semiconductor doped with the second conductivedopant. For instance, the second conductive semiconductor layer 116 mayinclude at least one selected from the group consisting of GaN, AlN,AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, andAlGaInP. If the second conductive semiconductor layer 116 is a P typesemiconductor layer, the second conductive dopant includes the P typedopant such as Mg, Zn, Ca, Sr, or Ba.

In addition, a third conductive semiconductor layer can be formed on thesecond conducive semiconductor layer 116. The third conductivesemiconductor layer may include a semiconductor having polarity oppositeto that of the second conductive semiconductor layer or identical tothat of the first conductive semiconductor layer.

The stack structure of the first conductive semiconductor layer 112, theactive layer 114 and the second conductive semiconductor layer 116 mayconstitute the light emitting cell areas. In addition, the lightemitting cell may include at least one of an N—P junction structure, aP—N junction structure, an N—P—N junction structure, and a P—N—Pjunction structure.

Referring to FIG. 4, a plurality of conductive contact layers 118 areformed on the second conductive semiconductor layer 116. The conductivecontact layers 118 are spaced apart from each other by a regularinterval. The ohmic contact layers 118 have widths corresponding to awidth of the each light emitting cell areas.

The ohmic contact layers 118 are formed on a part of the top surface ofthe second conductive semiconductor layer 116 while making ohmic contactwith the second conductive semiconductor layer 116. The ohmic contactlayers 118 may include transmissive conductive material. For instance,the ohmic contact layers 118 may include at least one selected from thegroup consisting of ITO (indium tin oxide), IZO (indium zinc oxide),IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO(aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zincoxide), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ITO.

The ohmic contact layers 118 can be prepared in the form of layers orpatterns. The layers or patterns may change ohmic resistance relative tothe second conductive semiconductor layer 116.

Referring to FIG. 5, a plurality of recesses 119 are formed. Therecesses 119 have a depth from the second conductive semiconductor layer116 to the top surface of the first conductive semiconductor layer 112.An interval T1 between the recesses 119 is predetermined. For instance,the interval T1 corresponds to a part of each electrode layer. The ohmiccontact layers 118 are formed on the top surface of the secondconductive semiconductor layer 116, which are divided into several partsby the recesses 119.

The sequence of forming the recesses 119 and the ohmic contact layers118 may be changeable, and the embodiment is not limited thereto.

Referring to FIG. 6, the first insulating layer 151 is formed on apredetermined region of the top surface of the second conductivesemiconductor layer 116 where the ohmic contact layers 118 are notformed. For instance, after forming a mask layer, the first insulatinglayer 151 is formed on a region where the mask layer is not formedthrough a lithography process. That is, the first insulating layer 151can be formed on the top surface of the second conductive semiconductorlayer 116 having no ohmic contact layers 118 and in the recesses 119.The first conductive semiconductor layer 112 is exposed through thefirst insulating layer 151 formed in the recesses 119.

Referring to FIGS. 7 and 8, the electrode layers 121, 122 and 123 areformed on the first insulating layer 151 and the ohmic contact layers118.

The electrode layers 121, 122 and 123 are physically spaced apart fromeach other and serve as reflective electrode layers. The electrodelayers 121, 122 and 123 may include material selected from the groupconsisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, W, Ti andcombination thereof.

The first electrode layer 121 is formed on the first insulating layer151 and partially makes contact with the first conductive semiconductorlayer 112 through the recesses 119. The second electrode layer 122 isformed on the first insulating layer 151 and the ohmic contact layers118 and partially makes contact with the first conductive semiconductorlayer 112 through the recesses 119. In addition, a plurality ofelectrode layers 121, 122 and 123 can be provided to make contact withthe first conductive semiconductor layer 112.

The third electrode layer 123 is formed on the ohmic contact layers 118and the first insulating layer 151. In FIG. 1, the third electrode layer123 is positioned corresponding to the third electrode layer 123 at thecenter of the light emitting device.

The second and third electrode layers 122 and 123 are positionedcorresponding to the light emitting cells, respectively. In addition, asshown in FIG. 1, the second and third electrode layers 122 and 123connect adjacent light emitting cells in series.

Referring to FIG. 8, the second electrode layer 155 is formed on thefirst and second electrode layers 121 and 122. The top surface of thethird electrode layer 123 is open.

The first and second insulating layers 151 and 155 may include materialselected from the group consisting of SiO₂, Si₃N₄, Al₂O₃, and TiO₂.

Referring to FIG. 9, a conductive support member 170 is formed on thesecond insulating layer 155 and the third electrode layer 123. Theconductive support member 170 supports the light emitting device andincludes at least one selected from the group consisting of Cu, Au, Ni,Mo, Cu—W, Pd, In, W, Si, Ta, Nb, and a carrier wafer such as Si, Ge,GaAs, ZnO, SiC, SiGe, Ga₂O₃ or GaN.

The conductive support member 170 may have heat sink and conductivecharacteristics. The conductive support member 170 can be coated orattached in the form of a sheet, but the embodiment is not limitedthereto. The conductive support member 170 may have a thickness of about30˜500 μm, but the embodiment is not limited thereto.

A bonding layer can be interposed between the conductive support member170 and the third electrode layer 123. The bonding layer may include atleast one of Ti, Cr, Ta, and an alloy thereof.

Referring to FIGS. 9 and 10, after the conductive support member 170 hasbeen positioned on the base, the substrate 110 is removed through aphysical/chemical scheme.

In order to remove the substrate 110, the physical and/or chemicalscheme can be employed. The physical scheme includes a laser lift off(LLO) scheme, in which a laser beam having a predetermined wavelengthband is irradiated onto the substrate 110, so that the substrate 110 isseparated from the first conductive semiconductor layer 112. Thechemical scheme includes a wet etching scheme, in which thesemiconductor layer (for instance, the buffer layer) formed between thesubstrate 110 and the first conductive semiconductor layer 112 isremoved through the wet etching process, so that the substrate 110 isseparated.

After the substrate 110 has been removed, an inductively coupledplasma/reactive ion etching (ICP/RIE) process can be performed withrespect to the surface of the first conductive semiconductor layer 112.

The ohmic contact layers 118 and the first to third electrode layers121, 122 and 123 are disposed under the second conductive semiconductorlayer 116 so that they are protected from external impact. That is, theohmic contact layers 118 and the first to third electrode layers 121,122 and 123 are protected from external impact when the substrate 110 isremoved.

Referring to FIG. 11, the etching process is performed to form thespacers 161 for the light emitting cells A1 to An. The etching processis continued until the first insulating layer 151 disposed under thesecond conductive semiconductor layer 116 is exposed. Thus, the lightemitting cells A1 to An may be separated from each other. Each lightemitting cell may be spaced apart from the part 126 of the electrodelayers 121, 122 and 123 by a predetermined distance D1. If the distanceD1 is enlarged, an ohmic contact layer can be further formed. Inaddition, the first insulating layer 151 may be exposed to the outersides of the light emitting cells A1 to An, but the embodiment is notlimited thereto.

The spacers 161 formed among the light emitting cells A1 to An may havewidths identical to or different from each other, and the embodiment isnot limited thereto. When viewed from the top, the light emitting cellsA1 to An may have a circular shape of a polygonal shape, such as arectangular shape or a square shape.

The part 126 of the first electrode layer 121 is connected to the firstconductive semiconductor layer 112 of the first light emitting cell A1.The second electrode layer 122 is connected to the ohmic contact layer118 disposed under the first light emitting cell 118 and the part 126 ofthe second electrode layer 122 is connected to the first conductivesemiconductor layer 112 of the second light emitting cell A2. In thismanner, the second electrode layer 122 connects two adjacent lightemitting cells in series.

The third electrode layer 123 is connected to the ohmic contact layer118 and the conductive support member 170 disposed under the nth lightemitting cell An. In this manner n light emitting cells A1 to An can beconnected to each other in series.

Referring to FIG. 12, the roughness 113 is formed on the top surface ofthe first conductive semiconductor layer 112 of the light emitting cellsA1 to An. The roughness 113 can be prepared in the form of aconcave-convex pattern through the dry and/or wet etching process. Inaddition, the roughness 113 may include an additional concave-convexstructure. The roughness 113 can improve the external quantumefficiency.

The first insulating layer 151 is partially exposed out of the firstlight emitting cell A1. A part of the first insulating layer 151 is openthrough the etching process. In this case, the first electrode layer 121may be exposed. The first electrode 171 is formed on the first electrodelayer 121. The first electrode 171 may include a pad.

The N light emitting cells A1 to An are connected with each other inseries between the first electrode 171 and the conductive support member170. Thus, the light emitting device as shown in FIG. 1 is obtainedthrough the manufacturing processes.

The embodiment can provide the light emitting device including the lightemitting cells of the first and second groups, which can be driven underthe AC power, so that additional parts may not be necessary even if theAC power is used and the light extraction efficiency can be improved.

FIG. 13 is a side sectional view showing a light emitting deviceaccording to the second embodiment. In the following description, theelements and structures that have already been explained in the firstembodiment will be omitted in order to avoid redundancy.

Referring to FIG. 13, the light emitting device 100A includes the secondinsulting layer 155 provided between the third electrode layer 123formed at the center of the light emitting device 100A and the supportmember 170A. The support member 170A includes material having the heatsink and insulating characteristics, so that the support member 170A caneffectively dissipate the heat. The support member 170A is formed of aconductive metal, but the embodiment is not limited thereto.

The light emitting cells A1 to An and Bn to B1 are connected to eachother in series between the first electrode 171 and the second electrode173 provided at both ends of the light emitting device 100A, so that thelight emitting device 100A can emit the light during the halfoperational period of the AC power. In this case, two light emittingdevices 100A is aligned in parallel to each other such that they can bedriven under the AC power.

FIG. 14 is a side sectional view showing a light emitting deviceaccording to the third embodiment. In the following description, theelements and structures that have already been explained in the firstembodiment will be omitted in order to avoid redundancy.

Referring to FIG. 14, the light emitting device 100B includes the secondinsulting layer 155 provided between the third electrode layer 123formed at the center of the light emitting device 100B and the supportmember 170.

The third electrode 175 can be formed in the spacer 161 aligned betweenthe first and second groups 101A and 103A. The third electrode 175 isformed on the third electrode layer 123 and connected to the nth lightemitting cell An of the first group 101 a and the nth light emittingcell Bn of the second group 103 a through the third electrode layer 123.

The first electrode layer 121 disposed under the first light emittingcell A1 of the first group 101A is connected to the support member 170and the fifth electrode layer 125 disposed under the first lightemitting cell B1 of the second group 103A is connected to the supportmember 170. Therefore, the light emitting cells A1 to An of the firstgroup 101A are operated during the half operational period of the ACpower and the light emitting cells B1 to Bn of the second group 103A areoperated during the remaining half operational period of the AC power.Details of the operation have already been described in the firstembodiment.

FIG. 15 is a sectional view showing a light emitting device packageincluding the light emitting device according to the embodiment.

Referring to FIG. 15, the light emitting device package 30 includes abody 20, first and second lead electrodes 32 and 33 formed on the body20, the light emitting device 100 provided on the body 20 andelectrically connected to the first and second lead electrodes 32 and 33and a molding member 40 that surrounds the light emitting device 100.

The body 20 may include at least one of silicon, synthetic resin, metalsapphire (Al2O3) and a PCB (printed circuit board). An inclined surfacemay be formed around the light emitting device 100. The body 20 may havea cavity 22, but the embodiment is not limited thereto.

The first and second lead electrodes 32 and 33 are electricallyseparated from each other to supply power to the light emitting device100. In addition, the first and second lead electrodes 32 and 33 reflectthe light emitted from the light emitting device 100 to improve thelight efficiency and dissipate heat generated from the light emittingdevice 100 to the outside.

Although FIG. 15 shows the first and second lead electrodes 32 and 33installed on the lower surface of the body 20, the embodiment is notlimited thereto.

For instance, the first and second lead electrodes 32 and 33 can beprovided on the body 20 and first and second pads can be formed on thelower surface of the body 20. In this case, the first and second leadelectrodes 32 and 33 can be electrically connected to the first andsecond pads through first and second conductive via holes formed throughthe body 20.

The light emitting device 100 can be installed on the body 20 or thefirst and second lead electrodes 32 and 33.

The light emitting device 100 can be electrically connected to at leastone of the first and second lead electrodes 32 and 33 through at leastone wire 25. For instance, the first and second electrodes of the lightemitting device 100 shown in FIG. 1 can be connected to the second leadelectrode 33 through a wire, and the conductive support member of thelight emitting device 100 can be formed on the first lead electrode 32through the die bonding scheme. In addition, the light emitting device100 can be electrically connected to the first and second leadelectrodes 32 and 33 through the flip chip bonding scheme or the diebonding scheme. One of the light emitting devices according to theembodiments can be selectively used as the light emitting device 100,and the embodiment is not limited thereto.

The molding member 40 includes silicon or resin having transmissiveproperty. The molding member 40 surrounds the light emitting device 100to protect the light emitting device 100. In addition, the moldingmember 40 may include phosphors to change the wavelength of the lightemitted from the light emitting device 100.

Although the top-view type light emitting device package is disclosed inthe embodiment, the side-view type light emitting device package can beused to improve the heat dissipation, conductivity and reflectivecharacteristics. According to the top-view type light emitting devicepackage or the side-view type light emitting device package, the lightemitting device is packaged by using the resin layer and then the lensis formed on or bonded to the resin layer, but the embodiment is notlimited thereto.

The light emitting device 100 is packaged and installed on the substrateto provide the light emitting module, or the light emitting device isprepared in the form of the LED to provide the light emitting module.

The light emitting module of the light unit includes the light emittingdevice package. The light emitting device package has the structure asshown in FIG. 15. Otherwise, the light emitting device according to theembodiment is installed on the substrate and packaged by the moldingmember.

<Lighting System>

The light emitting devices and the light emitting device packagesaccording to the embodiments may be applied to a light unit. The lightunit may have an array structure including a plurality of light emittingdevices or a plurality of light emitting device packages. The lightingsystem may include a display apparatus shown in FIGS. 16 and 17, a lightunit shown in FIG. 18, in addition to a lighting lamp, a signal light, avehicle headlight, an electronic display, etc.

FIG. 16 is a disassembled perspective view of a display apparatusaccording to an embodiment.

Referring to FIG. 16, the display apparatus 1000 according to theembodiment may include a light guide panel 1041, a light emitting module1031 supplying light to the light guide panel 1041, a reflective member1022 under the light guide panel 1041, an optical sheet 1051 on thelight guide panel 1041, a display panel 1061 on the optical sheet 1051,and a bottom cover 1011 receiving the light guide panel 1041, the lightemitting module 1031, and the reflective member 1022, but the presentdisclosure is not limited thereto.

The bottom cover 1011, the reflective sheet 1022, the light guide panel1041, and the optical sheet may be defined as a light unit 1041.

The light guide panel 1041 functions to transform linear light to planarlight by diffusing the linear light. The light guide panel 1041 may bemade of a transparent material, and may include one of acryl-seriesresin such as polymethyl metaacrylate (PMMA), polyethylene terephthlate(PET), poly carbonate (PC), COC, and polyethylene naphthalate resin.

The light emitting module 1031 provides light to at least a side surfaceof the light guide panel 1041, and finally acts as a light source of adisplay apparatus.

The light emitting module 1031 may include at least one light emittingmodule, and provide light directly or indirectly from one side surfaceof the light guide panel 1041. The light emitting module 1031 mayinclude a board 1033, and a light emitting device package 30 accordingto embodiments disclosed above, and the light emitting device packages30 may be arranged apart by a predetermined interval from each other onthe board 1033.

The board 1033 may be a printed circuit board (PCB) including a circuitpattern (not shown). The board 1033 may include a metal core PCB(MCPCB), a flexible PCB (FPCB), etc. as well as the general PCB, but thepresent disclosure is not limited thereto. In the case where the lightemitting device package 30 is mounted on a side surface or a heatreleasing plate, the board 1033 may be removed. Herein, some of the heatreleasing plate may contact an upper surface of the bottom cover 1011.

The plurality of light emitting device packages 30 may be mounted on theboard 1033 such that light emitting surfaces of the plurality of lightemitting device packages 30 are spaced apart by a predetermined distancefrom the light guide panel 1041, but the present disclosure is notlimited thereto. The light emitting device package 30 may supply lightto a light incident part that is one side surface of the light guidepanel 1041, directly or indirectly, but the present disclosure is notlimited thereto.

The reflective member 1022 may be provided under the light guide panel1041. The reflective member 1022 reflects light incident from a lowersurface of the light guide panel 1041 to allow the reflected light to bedirected toward an upper direction, thereby capable of enhancingbrightness of the light unit 1050. The reflective member 1022 may beformed of, for example, PET, PC, PVC resin, or the like, but the presentdisclosure is not limited thereto.

The bottom cover 1011 may receive the light guide panel 1041, the lightemitting module 1031, the reflective member 1022, and the like. For thispurpose, the bottom cover 1011 may have a receiving part 1012 formed ina box shape a top surface of which is opened, but the present disclosureis not limited thereto. The bottom cover 1011 may be coupled to a topcover, but the present disclosure is not limited thereto.

The bottom cover 1011 may be formed of a metal material or resinmaterial, and may be manufactured by using a process such as a pressmolding or an injection molding. Also, the bottom cover 1011 may includemetallic or nonmetallic material having a high thermal conductivity, butthe present disclosure is not limited thereto.

The display panel 1061 is, for example, an LCD panel, and includes firstand second transparent substrates facing each other, and a liquidcrystal layer interposed between the first and second substrates. Apolarizing plate may be attached on at least one surface of the displaypanel 1061, but the present disclosure is not limited thereto. Thedisplay panel 1061 displays information by using light passing throughthe optical sheet 1051. The display apparatus 1000 may be applied to avariety of mobile terminals, monitors for notebook computers, monitorsfor lap-top computers, televisions, etc.

The optical sheet 1051 is disposed between the display panel 1061 andthe light guide panel 1041, and includes at least one transparent sheet.The optical sheet 1051 may include, for example, at least one of adiffusion sheet, a horizontal and/or vertical prism sheet, and abrightness reinforcing sheet. The diffusion sheet diffuses incidentlight, the horizontal and/or vertical prism sheet focuses incident lighton a display region, and the brightness reinforcing sheet enhances thebrightness by reusing lost light. Also, a protective sheet may bedisposed on the display panel 1061, but the present disclosure is notlimited thereto. Herein, the display apparatus 1000 may include thelight guide panel 1041, and the optical sheet 1051 as optical memberspositioned on a light path of the light emitting module 1031, but thepresent disclosure is not limited thereto.

FIG. 17 is a cross-sectional view of a display apparatus according to anembodiment.

Referring to FIG. 17, the display apparatus 1100 includes a bottom cover1152, a board 1120 on which the light emitting device packages 30disclosed above are arrayed, an optical member 1154, and a display panel1155.

The board 1120 and the light emitting device package 30 may be definedas a light emitting module 1060. The bottom cover 1152, the at least onelight emitting module 1060, and the optical member 154 may be defined asa light unit.

The bottom cover 1152 may be provided with a receiving part, but thepresent disclosure is not limited thereto.

Herein, the optical member 1154 may include at least one of a lens, alight guide panel, a diffusion sheet, a horizontal and vertical prismsheet, and a brightness reinforcing sheet. The light guide panel may beformed of polycarbonate (PC) or poly methyl methacrylate (PMMA), and maybe removed. The diffusion sheet diffuses incident light, the horizontaland vertical prism sheet focuses incident light on a display region, andthe brightness reinforcing sheet enhances the brightness by reusing lostlight.

The optical member 1154 is disposed on the light emitting module 1060.The optical member 154 transforms light emitted from the light emittingmodule 1060 to planar light, and performs diffusion, light focusing, andthe like.

FIG. 18 is a perspective view of a lighting unit according to anembodiment.

Referring to FIG. 18, the lighting unit 1500 may include a case 1510, alight emitting module 1530 equipped in the case 1510, and a connectionterminal 1520 equipped in the case 1510 and supplied with an electricpower from an external power supply.

The case 1510 may be preferably formed of a material having good heatshielding characteristics, for example, a metal material or a resinmaterial.

The light emitting module 1530 may include a board 1532, and at leastone light emitting device package 30 according to the embodimentsmounted on the board 1532. The light emitting device package 30 mayinclude a plurality of light emitting device packages which are arrayedapart by a predetermined distance from one another in a matrixconfiguration.

The board 1532 may be an insulator substrate on which a circuit patternis printed, and may include, for example, a printed circuit board (PCB),a metal core PCB, a flexible PCB, a ceramic PCB, an FR-4 substrate, etc.

Also, the board 1532 may be formed of a material to efficiently reflectlight, and a surface thereof may be formed in a color capable ofefficiently reflecting light, for example, white color, or silver color.

The at least one light emitting device packages 30 may be mounted on theboard 1532. Each of the light emitting device packages 30 may include atleast one light emitting diode (LED) chip. The LED chip may include acolor LED emitting red, green, blue or white light, and a UV LEDemitting ultraviolet (UV).

The light emitting module 1530 may have a combination of various lightemitting device packages so as to obtain desired color and luminance.For example, the light emitting module 1530 may have a combination of awhite LED, a red LED, and a green LED so as to obtain a high colorrendering index (CRI).

The connection terminal 1520 may be electrically connected to the lightemitting module 1530 to supply power. The connection terminal 1520 maybe screwed and coupled to an external power in a socket type, but thepresent disclosure is not limited thereto. For example, the connectionterminal 1520 may be made in a pin type and inserted into an externalpower, or may be connected to the external power through a power line.

The light emitting module of the light unit includes the light emittingdevice packages. The light emitting device package may have a packagestructure using the body, or may be prepared by mounting the lightemitting devices disclosed above on the board and then packaging thelight emitting devices using the molding member.

The method of manufacturing the light emitting device includes the stepsof forming a first conductive semiconductor layer, an active layer and asecond conductive semiconductor layer on a growth substrate; forming aplurality of ohmic contact layers on the second conductive semiconductorlayer such that the ohmic contact layers are spaced apart from eachother; forming m (m>4) recesses through an etching process to expose thefirst conductive semiconductor layer; forming a first insulating layeron the second conductive semiconductor layer and around the recesses,forming a second insulating layer except for a region where a centralelectrode layer is formed; forming a conductive support member on thesecond insulating layer and the central electrode layer; removing thesubstrate, exposing the second insulating layer through an etchingprocess to provide m light emitting cells (m≧4), and connecting the mlight emitting cells to each other in series; and forming a firstelectrode connected to the first conductive semiconductor layer of thefirst light emitting cell and a second electrode connected to anelectrode layer disposed under the last light emitting cell.

The embodiment can provide the light emitting device driven under the ACpower. The embodiment can drive the light emitting device used for thehigh-voltage AC power. The embodiment can provide the light emittingdevice having thermal stability. The embodiment can provide the lightemitting apparatus operated under the AC power by connecting a pluralityof light emitting devices having a plurality of serial light emittingcells in series, parallel or anti-parallel configuration.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting device comprising: a pluralityof light emitting cells including a first and second light emittingcells spaced apart from each other, each of the first and second lightemitting cells including a first semiconductor layer, a secondsemiconductor layer under the first semiconductor layer, and an activelayer between the first semiconductor layer and the second semiconductorlayer; a conductive support member under the first and second lightemitting cells; a first conducive layer between the first light emittingcell and the conductive support member; a second conductive layerbetween the first conductive layer and the conductive support member; athird conductive layer between the second light emitting cell and theconductive support member; a fourth conductive layer between the thirdconductive layer and the conductive support member; a first insulatinglayer between the second and fourth conductive layers and the conductivesupport member; a first hole disposed in the active layer and the secondsemiconductor layer of the first light emitting cell; a second holedisposed in the active layer and the second semiconductor layer of thesecond light emitting cells; and a second insulating layer disposed inthe first hole and the second hole, wherein the second conductive layerincludes a first portion disposed in the first hole and is electricallyconnected to the first semiconductor layer of the first light emittingcells by the first portion and the third conductive layer.
 2. The lightemitting device as claimed in claim 1, further comprising a fifthconductive layer under a lower surface of the first conductive layer ofthe first light emitting cell.
 3. The light emitting device as claimedin claim 2, wherein the fifth conductive layer is connected to the firstconductive layer of the first light emitting cell.
 4. The light emittingdevice as claimed in claim 3, wherein a first portion of the fifthconductive layer is extended outwardly from a lower portion of the firstlight emitting cell.
 5. The light emitting device as claimed in claim 4,further comprising a first electrode disposed on the first portion ofthe fifth conductive layer.
 6. The light emitting device as claimed inclaim 5, wherein a first portion of the conductive support memberextends under the first portion of the fifth conductive layer.
 7. Thelight emitting device as claimed in claim 1, further comprising a thirdinsulating surrounding side surfaces of the first and second lightemitting cells.
 8. The light emitting device as claimed in claim 1,further comprising a third insulating layer surrounding side surfaces ofthe first and second light emitting cells.
 9. The light emitting deviceas claimed in claim 8, wherein a portion of the third insulating layeris disposed on a top surface of the first and second light emittingcells.
 10. The light emitting device as claimed in claim 1, furthercomprising a roughness disposed on the first semiconductor layers of thefirst and second light emitting cells.
 11. The light emitting device asclaimed in claim 1, wherein the first semiconductor layer has an n-typedopant and the second semiconductor layer has a p-type dopant.
 12. Thelight emitting device as claimed in claim 1, wherein the secondconductive layer includes a second portion extending under a lowersurface of the third conductive layer.
 13. The light emitting device asclaimed in claim 1, wherein the conductive support member includes a topsurface having a width wider than a sum of widths of the plurality oflight emitting cells, wherein an entire top surface of the conductivesupport member is formed in a flat surface.
 14. The light emittingdevice as claimed in claim 1, wherein the plurality of light emittingcells includes a third light emitting cell including a firstsemiconductor layer, a second semiconductor layer under the firstsemiconductor layer, and an active layer between the first semiconductorlayer and the second semiconductor layer.
 15. The light emitting deviceas claimed in claim 1, wherein the conductive support member isconnected to the first semiconductor layer of the third light emittingcell.
 16. The light emitting device as claimed in claim 1, wherein a topregion between side surfaces of the first and second light emittingcells includes an opened region in upward direction.
 17. The lightemitting device as claimed in claim 1, wherein a portion of the firstinsulating layer is disposed between the second conductive layer and thefourth conductive layer.
 18. The light emitting device as claimed inclaim 1, wherein a lower surface of the second semiconductor layers ofthe first and second light emitting cells is located at a higherposition than that of the first conductive layer and the thirdconductive layer.